sh: Use generic idle loop

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Link: http://lkml.kernel.org/r/20130321215235.216323644@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 14 insertions, 91 deletions

diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 5e859633ce69..853cbc971cdf 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -33,6 +33,8 @@ config SUPERH
         select GENERIC_ATOMIC64
         select GENERIC_IRQ_SHOW
         select GENERIC_SMP_IDLE_THREAD
+        select GENERIC_IDLE_LOOP
+        select GENERIC_IDLE_POLL_SETUP
         select GENERIC_CLOCKEVENTS
         select GENERIC_CMOS_UPDATE if SH_SH03 || SH_DREAMCAST
         select GENERIC_STRNCPY_FROM_USER
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 3d5a1b387cc0..2ea4483fd722 100644
--- a/arch/sh/kernel/idle.c
+++ b/arch/sh/kernel/idle.c
@@ -24,98 +24,24 @@
 
 static void (*sh_idle)(void);
 
-static int hlt_counter;
-
-static int __init nohlt_setup(char *__unused)
-{
-        hlt_counter = 1;
-        return 1;
-}
-__setup("nohlt", nohlt_setup);
-
-static int __init hlt_setup(char *__unused)
-{
-        hlt_counter = 0;
-        return 1;
-}
-__setup("hlt", hlt_setup);
-
-static inline int hlt_works(void)
-{
-        return !hlt_counter;
-}
-
-/*
- * On SMP it's slightly faster (but much more power-consuming!)
- * to poll the ->work.need_resched flag instead of waiting for the
- * cross-CPU IPI to arrive. Use this option with caution.
- */
-static void poll_idle(void)
+void default_idle(void)
 {
+        set_bl_bit();
         local_irq_enable();
-        while (!need_resched())
-                cpu_relax();
+        /* Isn't this racy ? */
+        cpu_sleep();
+        clear_bl_bit();
 }
 
-void default_idle(void)
+void arch_cpu_idle_dead(void)
 {
-        if (hlt_works()) {
-                clear_thread_flag(TIF_POLLING_NRFLAG);
-                smp_mb__after_clear_bit();
-
-                set_bl_bit();
-                if (!need_resched()) {
-                        local_irq_enable();
-                        cpu_sleep();
-                } else
-                        local_irq_enable();
-
-                set_thread_flag(TIF_POLLING_NRFLAG);
-                clear_bl_bit();
-        } else
-                poll_idle();
+        play_dead();
 }
 
-/*
- * The idle thread. There's no useful work to be done, so just try to conserve
- * power and have a low exit latency (ie sit in a loop waiting for somebody to
- * say that they'd like to reschedule)
- */
-void cpu_idle(void)
+void arch_cpu_idle(void)
 {
-        unsigned int cpu = smp_processor_id();
-
-        set_thread_flag(TIF_POLLING_NRFLAG);
-
-        /* endless idle loop with no priority at all */
-        while (1) {
-                tick_nohz_idle_enter();
-                rcu_idle_enter();
-
-                while (!need_resched()) {
-                        check_pgt_cache();
-                        rmb();
-
-                        if (cpu_is_offline(cpu))
-                                play_dead();
-
-                        local_irq_disable();
-                        /* Don't trace irqs off for idle */
-                        stop_critical_timings();
-                        if (cpuidle_idle_call())
-                                sh_idle();
-                        /*
-                         * Sanity check to ensure that sh_idle() returns
-                         * with IRQs enabled
-                         */
-                        WARN_ON(irqs_disabled());
-                        start_critical_timings();
-                }
-
-                rcu_idle_exit();
-                tick_nohz_idle_exit();
-                schedule_preempt_disabled();
-        }
+        if (cpuidle_idle_call())
+                sh_idle();
 }
 
 void __init select_idle_routine(void)
@@ -123,13 +49,8 @@ void __init select_idle_routine(void)
         /*
          * If a platform has set its own idle routine, leave it alone.
          */
-        if (sh_idle)
-                return;
-
-        if (hlt_works())
+        if (!sh_idle)
                 sh_idle = default_idle;
-        else
-                sh_idle = poll_idle;
 }
 
 void stop_this_cpu(void *unused)
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index 2062aa88af41..45696451f0ea 100644
--- a/arch/sh/kernel/smp.c
+++ b/arch/sh/kernel/smp.c
@@ -203,7 +203,7 @@ asmlinkage void __cpuinit start_secondary(void)
         set_cpu_online(cpu, true);
         per_cpu(cpu_state, cpu) = CPU_ONLINE;
 
-        cpu_idle();
+        cpu_startup_entry(CPUHP_ONLINE);
 }
 
 extern struct {